Seasonal variations in cardiovascular disease

Excess mortality at Christmas due to cardiovascular disease in the HUNT study prospective population-based cohort in Norway

Background

Although it is known that winter inclusive of the Christmas holiday period is associated with an increased risk of dying compared to other times of the year, very few studies have specifically examined this phenomenon within a population cohort subject to baseline profiling and prospective follow-up. In such a cohort, we sought to determine the specific characteristics of mortality occuring during the Christmas holidays.

Methods

Baseline profiling and outcome data were derived from a prospective population-based cohort with longitudinal follow-up in Central Norway - the Trøndelag Health (HUNT) Study. From 1984 to 1986, 88% of the target population comprising 39,273 men and 40,353 women aged 48 ± 18 and 50 ± 18 years, respectively, were profiled. We examined the long-term pattern of mortality to determine the number of excess (all-cause and cause-specific) deaths that occurred during winter overall and, more specifically, the Christmas holidays.

Results

During 33.5 (IQR 17.1–34.4) years follow-up, 19,879 (50.7%) men and 19,316 (49.3%) women died at age-adjusted rate of 5.3 and 4.6 deaths per 1000/annum, respectively. Overall, 1540 (95% CI 43–45 deaths/season) more all-cause deaths occurred in winter (December to February) versus summer (June to August), with 735 (95% CI 20–22 deaths per season) of these cardiovascular-related. December 25th–27th was the deadliest 3-day period of the year; being associated with 138 (95% CI 96–147) and 102 (95% CI 72–132) excess all-cause and cardiovascular-related deaths, respectively. Accordingly, compared to 1st–21st December (equivalent winter conditions), the incidence rate ratio of all-cause mortality increased to 1.22 (95% CI 1.16–1.27) and 1.17 (95% 1.11–1.22) in men and women, respectively, during the next 21 days (Christmas/New Year holidays). All observed differences were highly significant (P < 0.001). A less pronounced pattern of mortality due to respiratory illnesses (but not cancer) was also observed.

Conclusion

Beyond a broader pattern of seasonally-linked mortality characterised by excess winter deaths, the deadliest time of year in Central Norway coincides with the Christmas holidays. During this time, the pattern and frequency of cardiovascular-related mortality changes markedly; contrasting with a more stable pattern of cancer-related mortality. Pending confirmation in other populations and climates, further research to determine if these excess deaths are preventable is warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10503-7.

Temporal patterns of suicide and circulatory system disease-related mortality are inversely correlated in several countries

BACKGROUND

Nearly 800,000 suicides occur worldwide annually and suicide rates are increasing faster than population growth. Unfortunately, the pathophysiology of suicide remains poorly understood, which has hindered suicide prevention efforts. However, mechanistic clues may be found by studying effects of seasonality on suicide and other mortality causes. Suicides tend to peak in spring-summer periods and nadir in fall-winter periods while circulatory system disease-related mortality tends to exhibit the opposite temporal trends. This study aimed to determine for the first time whether monthly temporal cross-correlations exist between suicide and circulatory system disease-related mortality at the population level. If so and if common biological factors moderate risks for both mortality types, such factors may be discoverable and utilized to improve suicide prevention.

METHODS

We conducted time series analyses of monthly mortality data from northern (England and Wales, South Korea, United States) and southern (Australia, Brazil) hemisphere countries during the period 2009-2018 (N = 41.8 million all-cause mortality cases). We used a Poisson regression variant of the standard cosinor model to determine peak months of mortality. We also estimated cross-correlations between monthly mortality counts from suicide and from circulatory system diseases.

RESULTS

Suicide and circulatory disease-related mortality temporal patterns were negatively correlated in Australia (- 0.32), Brazil (- 0.57), South Korea (- 0.32), and in the United States (- 0.66), but no temporal correlation was discernable in England and Wales.

CONCLUSIONS

The negative temporal cross-correlations between these mortality types we found in 4 of 5 countries studied suggest that seasonal factors broadly and inversely moderate risks for circulatory disease-related mortality and suicide, but not in all regions, indicating that the effect is not uniform. Since the seasonal factors of temperature and light exert opposite effects on suicide and circulatory disease-related mortality in several countries, we propose that physiologically-adaptive circulatory system responses to heat and light may increase risk for suicide and should be studied to determine whether they affect suicide risk. For example, heat and light increase production and release of the bioactive gas nitric oxide and reduce circulatory system disease by relaxing blood vessel tone, while elevated nitric oxide levels are associated with suicidal behavior, inverse effects that parallel the inverse temporal mortality patterns we detected.

SARS-CoV 2 Infection (Covid-19) and Cardiovascular Disease in Africa: Health Care and Socio-Economic Implications

The current pandemic of SARS-COV 2 infection (Covid-19) is challenging health systems and communities worldwide. At the individual level, the main biological system involved in Covid-19 is the respiratory system. Respiratory complications range from mild flu-like illness symptoms to a fatal respiratory distress syndrome or a severe and fulminant pneumonia. Critically, the presence of a pre-existing cardiovascular disease or its risk factors, such as hypertension or type II diabetes mellitus, increases the chance of having severe complications (including death) if infected by the virus. In addition, the infection can worsen an existing cardiovascular disease or precipitate new ones. This paper presents a contemporary review of cardiovascular complications of Covid-19. It also specifically examines the impact of the disease on those already vulnerable and on the poorly resourced health systems of Africa as well as the potential broader consequences on the socio-economic health of this region.

Reduction of Emergency Calls and Hospitalizations for Cardiac Causes: Effects of Covid-19 Pandemic and Lockdown in Tuscany Region

Introduction: Containment measures were established to flatten the curve of COVID-19 contagion in order to avoid a crash of the healthcare system. However, these measures influenced the rate of hospitalization of cardiac patients. In this study, we aimed to analyse the impact of COVID-19 and the effects of lockdown measures on hospital admissions and alerts of emergency medical system (EMS) for cardiac causes in the Tuscany region.

Methods: An observational, retrospective analysis from Italian Tuscany region was conducted. We evaluated consecutive patients contacting EMS or admitted to the 39 Emergency Departments (EDs) in Tuscany for cardiac causes in the first trimester of 2020. Data were compared with the same period in 2018/19.

Results: The alerts of EMS for cardiac causes significantly decrease in 2020 and the highest difference between 2018/19 and 2020 was found immediately after national lockdown (Δ = −47.4%, p < 0.001). The number of admissions for chest pain in the EDs also decreased, with a maximum difference of −67.6% (p < 0.001) vs. 2018/19. The number of hospital accesses for acute coronary syndromes, atrial fibrillation, and heart failure in the EDs significantly decreased in 2020 as compared to 2018/19 (maximum Δ = −58.9%, p < 0.001; maximum Δ = −63.0%, p < 0.001; maximum Δ = −72.7%, p < 0.001, respectively).

Conclusions: A significant decrease in the contacts to EMS for cardiac causes and in cardiac diagnoses was observed during the first trimester of 2020. Fear of contagion has likely played a relevant role. The lesson learnt from first wave of COVID-19 pandemic suggests that appropriate public information strategies and re-education of people are essential.

Lopsided Blood-Thinning Drug Increases the Risk of Internal Flow Choking Leading to Shock Wave Generation Causing Asymptomatic Cardiovascular Disease

The discovery of Sanal flow choking in the cardiovascular-system calls for multidisciplinary and global action to develop innovative treatments and to develop new drugs to negate the risk of asymptomatic-cardiovascular-diseases. Herein, it is shown that when blood-pressure-ratio (BPR) reaches the lower-critical-hemorrhage-index (LCHI) internal-flow-choking and shock wave generation can occur in the cardiovascular-system, with sudden expansion/divergence/vasospasm or bifurcation regions, without prejudice to the percutaneous-coronary-intervention (PCI). Analytical findings reveal that the relatively high and the low blood-viscosity are cardiovascular-risk factors. In vitro studies have shown that nitrogen, oxygen, and carbon dioxide gases are dominant in fresh blood samples of humans/guinea pigs at a temperature range of 98.6-104 F. An in silico study demonstrated the Sanal flow choking phenomenon leading to shock-wave generation and pressure-overshoot in the cardiovascular-system. It has been established that disproportionate blood-thinning treatment increases the risk of the internal-flow-choking due to the enhanced boundary-layer-blockage-factor, resulting from an increase in flow-turbulence level in the cardiovascular-system, caused by an increase in Reynolds number as a consequence of low blood-viscosity. The cardiovascular-risk can be diminished by concurrently lessening the viscosity of biofluid/blood and flow-turbulence by raising the thermal-tolerance-level in terms of blood-heat-capacity-ratio (BHCR) and/or by decreasing the systolic-to-diastolic blood-pressure-ratio.

Seasonal fluctuation of erectile dysfunction: A cross-sectional study from a tertiary university hospital across 10 years

Erectile dysfunction (ED) shares several risk factors with diabetes mellitus (DM), hypertension (HT) and coronary vascular disease (CVD), which were well-associated with seasonal fluctuation with the highest peak in winter. In this study, we aimed to determine whether ED demonstrates seasonal fluctuations with the above-mentioned systemic diseases. Database from a tertiary university hospital between 2010 and 2020 was deciphered to retrieve patients diagnosed with ED. Patients with primary bladder tumour and post-procedural ED constituted the negative control groups from the same study period. International index of erectile function questionnaire (IIEF-15) was used to segregate included patients into mild/moderate and severe ED groups. The probability of detecting DM, HT and CVD in patients with severe ED was significantly higher than that of with mild/moderate ED (p < 0.05). More ED symptoms emerged and were diagnosed in the winter seasons even though no statistical significance was observed between patients with mild/moderate and severe ED (p = 0.946, Cramer's V coefficient = 0.19). The seasonal variation of patients with bladder tumour and post-procedural ED groups showed no significant difference (p > 0.05, both). ED admissions are associated with higher peaks in the winter seasons. This may help in daily clinical practice to warrant better clinical and epidemiological interpretation of ED.

Rapid Rise of Cardio-Ankle Vascular Index May Be a Trigger of Cerebro-Cardiovascular Events: Proposal of Smooth Muscle Cell Contraction Theory for Plaque Rupture

Cardiovascular diseases have been recognized as the main cause of death all over the world. Recently, the established cardio-ankle vascular index (CAVI) has become known as an index of arterial stiffness of the arterial tree from the origin of the aorta to the ankle. CAVI reflects the progress of arteriosclerosis, and a rapid rise in CAVI indicates arterial smooth muscle cell contraction. Considering the vasculature of the atheroma where vasa vasorum penetrates the smooth muscle cell layer and supplies blood to the intimal atheromatous lesion, a rapid rise of CAVI means "choked" atheroma. Thus, we proposed a "smooth muscle cell contraction" hypothesis of plaque rupture.

Increase in searches for erectile dysfunction during winter: seasonal variation evidence from Google Trends in the United States

Several diseases associated with erectile dysfunction (ED), such as type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD), are known to have seasonal variation, with increased incidence during winter months. However, no literature exists on whether this chronological-seasonal evolution is also present within ED symptomatology. We hypothesized ED would follow the seasonal pattern of its lifestyle-influenced comorbid conditions and exhibit increased incidence during winter months. In order to investigate the seasonal variation of ED in the United States between 2009 and 2019, Internet search query data were obtained using Google Trends. Normalized search volume was determined during the winter and summer seasons for ED, other diseases known to be significantly associated with ED (T2DM and CAD), kidney stones (positive control), and prostate cancer (negative control). There were significantly more internet search queries for ED during the winter than during the summer (p = 0.001). CAD and T2DM also had significantly increased search volume during winter months compared to summer months (p < 0.001 and p = 0.011, respectively). By contrast, searches for kidney stones were significantly increased in the summer than in the winter (p < 0.001). There was no significant seasonal variation in the relative search frequency for prostate cancer (p = 0.75). In conclusion, Google Trends internet search data across a ten-year period in the United States suggested a seasonal variation in ED, which implies an increase in ED during winter. This novel finding in ED epidemiology may help increase awareness of ED’s associated lifestyle risk factors, which may facilitate early medical evaluation and treatment for those at risk of both ED and cardiovascular disease.

Clinical correlates of seasonality in bipolar disorder: A specifier that needs specification?

OBJECTIVE

Seasonal pattern (SP) is a bipolar disorder (BD) specifier that indicates a tendency towards affective relapses during specific moments of the year. SP affects 15%-25% of BD patients. In the past, SP was applied only to depressive relapses while, in DSM-5, SP may be applied to both depressive and (hypo)manic episodes. We examined the association between different clinical correlates of BD and SP according to its current definition in a cohort of patients with BD type I (BDI) and II (BDII).

METHODS

Patients were recruited from a specialized unit and assessed according to the season of relapse and type of episode per season. SP and non-SP patients were compared looking into sociodemographic and clinical correlates. Significant variables at univariate comparisons were included in multivariate logistic regression with SP as the dependent variable.

RESULTS

708 patients were enrolled (503 BDI, 205 BDII), and 117 (16.5%) fulfilled DSM-5 criteria for SP. The mean age was 45.3 years (SD = 14.18), and 389 were female (54.9%). The logistic regression model included a significant contribution of BDII (OR = 2.23, CI 1.4-3.55), family history of mood disorder (OR = 1.97, CI 1.29-3.01), undetermined predominant polarity (OR = 0.44, CI 0.28-0.70), and aggressive behavior (OR = 0.42, CI 0.23-0.75).

CONCLUSION

Our results outline a novel positive association of SP with undetermined predominant polarity, BDII, family history of mood disorder, and with fewer aggressiveness-related symptoms. Seasonality is associated with a biphasic pattern with similar dominance of (hypo)mania and depression and is more frequent in BDII as compared to BDI. Seasonal episodes may be easier to predict, but difficult to prevent.

Seasonality of acute kidney injury in a tertiary hospital academic center: an observational cohort study

BACKGROUND

The aim of our study was to describe seasonal trends of acute kidney injury (AKI) and its relationship with weather conditions in a hospitalized population.

METHODS

We retrospectively collected demographic (age, sex), clinical (ICD-9-CM codes of diagnosis discharge) and laboratory data (creatinine values) from the inpatient population admitted to Fondazione Policlinico Universitario A. Gemelli IRCCS between January 2010 and December 2014 with inclusion of all patients ≥18 years with at least two values available for creatinine. The outcome of interest was AKI development, defined according to creatinine kinetics criteria. The exposures of interest were the months and seasons of the year; air temperature and humidity level were also evaluated. Log-binomial regression models adjusted for age, sex, eGFR, comorbidities, Charlson/Deyo index score, year of hospitalization were used to estimate risk ratios (RR) and 95% confidential intervals (CI).

RESULTS

A total of 64,610 patients met the inclusion criteria. AKI occurred in 2864 (4.4%) hospital admissions. After full adjustment, winter period was associated with increased risk of AKI (RR 1.16, 95% CI 1.05, 1.29, p=0.003). Lower air temperature and higher humidity level were associated with risk of AKI, however in multivariable-adjusted models only higher humidity level showed a significant and independent association.

CONCLUSIONS

AKI is one of the most common complications of hospitalized populations with a defined seasonal pattern and a significant increase in incidence during wintertime; weather conditions, particularly higher humidity level, are independent predictors of AKI and could partially justify the observed seasonal variations.

Seasonal variability of the vitamin D effect on physical fitness in adolescents

Studies investigating the relationship between vitamin D and physical fitness in youth have provided inconsistent findings. Recent evidence indicates that the expression of receptors and vitamin D-modulated genes in young subjects has a seasonal profile. Therefore, we investigated the role of vitamin D on physical fitness across seasons in a total of 977 male adolescents. Anthropometrics, lifestyle, dietary habits, biochemical profiles and physical fitness were studied. Multiple linear regression models, including pairwise interaction terms involving total 25-OH-vitamin D, were fitted. The interacting effect of season and total 25-OH-vitamin D had a significant influence on physical fitness performance (spring and total 25-OH-vitamin D: ß 0.19, SE 0.07, p = 0.007; summer and total 25-OH-vitamin D: ß 0.10, SE 0.06, p = 0.11; autumn and total 25-OH-vitamin D: ß 0.18, SE 0.07, p = 0.01), whereas the main effect of total 25-OH-vitamin D alone was not significant (p = 0.30). Body fat percentage, recreational physical activity level, time spent per day gaming/TV-watching, smoking, and hemoglobin levels were also related to the physical fitness performance score. Future studies should further explore the role of seasonal-dependent effects of vitamin D on health.

Extreme temperatures and cardiovascular mortality: assessing effect modification by subgroups in Ganzhou, China

Background

Many people die from cardiovascular diseases each year, and extreme temperatures are regarded as a risk factor for cardiovascular deaths. However, the relationship between temperature and cardiovascular deaths varies in different regions because of population density, demographic inequality, and economic situation, and the evidence in Ganzhou, China is limited and inconclusive.

Objective

This study aimed to assess extreme temperature-related cardiovascular mortality and identify the potential vulnerable people.

Methods

After controlling other meteorological measures, air pollution, seasonality, relative humidity, day of the week, and public holidays, we examined temperature-related cardiovascular mortality along 21 lag days by Poisson in Ganzhou, China.

Results

A J-shaped relationship was observed between mean temperature and cardiovascular mortality. Extremely low temperatures substantially increased the relative risks (RR) of cardiovascular mortality. The effect of cold temperature was delayed by 2–6 days and persisted for 4–10 days. However, the risk of cardiovascular mortality related to extremely high temperatures was not significant (p > 0.05). Subgroup analysis indicated that extremely low temperatures had a stronger association with cardiovascular mortality in people with cerebrovascular diseases (RR: 1.282, 95% confidence interval [CI]: 1.020–1.611), males (RR: 1.492, 95% CI: 1.175–1.896), married people (RR: 1.590, 95% CI: 1.224–2.064), and people above the age of 65 years (RR: 1.641, 95% CI: 1.106–2.434) than in people with ischemic heart disease, females, unmarried people, and the elderly (≥65 years old), respectively.

Conclusions

The type of cardiovascular disease, sex, age, and marital status modified the effects of extremely low temperatures on the risk of cardiovascular mortality. These findings may help local governments to establish warning systems and precautionary measures to reduce temperature-related cardiovascular mortality.

Determinants of personal exposure to PM2.5 and black carbon in Chinese adults: A repeated-measures study in villages using solid fuel energy

Exposure to air pollution is a leading health risk factor. The variance components and contributions of indoor versus outdoor source determinants of personal exposure to air pollution are poorly understood, especially in settings of household solid fuel use. We conducted a panel study with up to 4 days of repeated measures of integrated gravimetric personal exposure to PM2.5 and black carbon in 787 men and women (ages 40-79) living in peri-urban villages in northern (Beijing and Shanxi) and southern (Guangxi) China. We simultaneously measured outdoor PM2.5 and collected questionnaire data on sociodemographic characteristics and indoor pollution sources including tobacco smoking and solid fuel stove use. We obtained over 2000 days of personal exposure monitoring which showed higher exposures in the heating season (geometric mean (GM): 108 versus 65 μg/m3 in the non-heating season for PM2.5) and among northern participants (GM: 90 versus 59 μg/m3 in southern China in the non-heating season for PM2.5). We used mixed-effects models to estimate within- and between-participant variance components and to assess the determinants of exposures. Within-participant variance in exposure dominated the total variability (68-95%). Outdoor PM2.5 was the dominant variable for explaining within-participant variance in exposure to PM2.5 (16%). Household fuel use (PM2.5: 8%; black carbon: 10%) and smoking status (PM2.5: 27%; black carbon: 5%) explained the most between-participant variance. Indoor sources (solid fuel stoves, tobacco smoking) were associated with 13-30% higher exposures to air pollution and each 10 μg/m3 increase in outdoor PM2.5 was associated with 6-8% higher exposure. Our findings indicate that repeated measurements of daily exposure are likely needed to capture longer-term exposures in settings of household solid fuel use, even within a single season, and that reducing air pollution from both outdoor and indoor sources is likely needed to achieve measurable reductions in exposures to air pollution.

Risk Factors for Frailty in Critical Care Survivors: A secondary analysis

OBJECTIVES

The purpose of this study was to investigate the prevalence of frailty and its risk factors among critical care survivors who were discharged after receiving treatment in an intensive care unit.

METHODS

This was a secondary analysis using data from a methodological study conducted between June and August 2018. The sample included 494 adults who had been admitted to the intensive care unit for more than 48 hours within a year. Only post-intensive care frailty was evaluated using the Kihon Checklist. The sociodemographic and intensive care-related risk factors for frailty were analysed using multivariate logistic regression.

RESULTS

The prevalence of frailty in the sample was 65.8%. The risk factors for frailty were female sex (adjusted odds ratio [aOR] = 1.68, 95% CI: 1.02-2.78), aged 70 years or older (aOR = 4.16, 95% CI: 2.00-8.65), unemployment (aOR = 2.41, 95% CI: 1.39-4.17) and longer ICU days (aOR = 2.29, 95% CI: 1.35-3.91). Analysis of differences in risk factors according to sex revealed that risk factors for frailty were unemployment and longer ICU length of stay for male and older age for female.

CONCLUSION

Health care providers should be aware of frailty risk factors in female and male patients and provide patient-specific interventions for preventing frailty.

Cold weather-related cardiorespiratory symptoms predict higher morbidity and mortality

BACKGROUND

Symptoms perceived in cold weather reflect physiological responses to body cooling and may worsen the course of a pre-existing disease or precipitate disease events in ostensibly healthy individuals. However, the associations between cold-related symptoms and their health effects have remained unknown. We examined whether cold-related cardiac and respiratory symptoms perceived in cold weather predict future morbidity and mortality.

METHODS

Cold-related symptoms were inquired in four national FINRISK surveys conducted in 1997, 2002, 2007, 2012 in Finland including altogether 17 040 respondents. A record linkage was made to national hospital discharge and cause-of-death registers. The participants were followed up until the first hospital admission due to a cardiovascular or respiratory disease or death, or until the end of 2015. The individual follow-up times ranged from 0 to 18 years (mean 11 years). The association of cold-related symptoms with morbidity and mortality was examined by Kaplan-Meyer and Cox-regression analyses.

RESULTS

Cold-related cardiac [hazard ratio (HR), 1.76 and its 95% confidence interval (95% CI), 1.44-2.15] and combined cardiac and respiratory symptoms [1.50 (1.29-1.73)] were associated with hospitalization due to cardiovascular causes. The respective HRs for admissions due to respiratory causes were elevated for cold-related respiratory [1.22 (1.07-1.40)], cardiac [1.24 (0.88-1.75)] and cardiorespiratory [1.82 (1.50-2.22)] symptoms. Cold-related cardiorespiratory symptoms were associated with deaths from all natural [1.38 (1.11-1.72)], cardiovascular [1.77 (1.28-2.44)] and respiratory [2.19 (0.95-5.06)] causes.

INTERPRETATION

Cold weather-related symptoms predict a higher occurrence of hospital admissions and mortality. The information may prove useful in planning measures to reduce cold-related adverse health effects.

Thermal Personalities of Older People in South Australia: A Personas-Based Approach to Develop Thermal Comfort Guidelines

An important consideration for future age-friendly cities is that older people are able to live in housing appropriate for their needs. While thermal comfort in the home is vital for the health and well-being of older people, there are currently few guidelines about how to achieve this. This study is part of a research project that aims to improve the thermal environment of housing for older Australians by investigating the thermal comfort of older people living independently in South Australia and developing thermal comfort guidelines for people ageing-in-place. This paper describes the approach fundamental for developing the guidelines, using data from the study participants' and the concept of personas to develop a number of discrete "thermal personalities". Hierarchical Cluster Analysis (HCA) was implemented to analyse the features of research participants, resulting in six distinct clusters. Quantitative and qualitative data from earlier stages of the project were then used to develop the thermal personalities of each cluster. The thermal personalities represent different approaches to achieving thermal comfort, taking into account a wide range of factors including personal characteristics, ideas, beliefs and knowledge, house type, and location. Basing the guidelines on thermal personalities highlights the heterogeneity of older people and the context-dependent nature of thermal comfort in the home and will make the guidelines more user-friendly and useful.

Health effects of heat vulnerability in Rio de Janeiro: a validation model for policy applications

Extreme heat events can lead to increased risk of heat-related deaths. Furthermore, urban areas are often hotter than their rural surroundings, exacerbating heat waves. Unfortunately, validation is difficult; to our knowledge, most validations, even if they control for temperatures, really only validate a social vulnerability index instead of a heat vulnerability index. Here we investigate how to construct and validate a heat vulnerability index given uncertainty ranges in data for the city of Rio de Janeiro. First, we compare excess deaths of certain types of circulatory diseases during heat waves. Second, we use demographic and environmental data and factor analysis to construct a set of unobserved factors and respective weightings related to heat vulnerability, including a Monte Carlo analysis to represent the uncertainty ranges assigned to the input data. Finally, we use distance to hospital and clinics and their health record data as an instrumental variable to validate our factors. We find that we can validate the Rio de Janeiro heat vulnerability index against excess deaths during heat waves; specifically, we use three types of regressions coupled with difference in difference calculations to show this is indeed a heat vulnerability index as opposed to a social vulnerability index. The factor analysis identifies two factors that contribute to >70% of the variability in the data; one socio-economic factor and one urban form factor. This suggests it is necessary to add a step to existing methods for validation of heat vulnerability indices, that of the difference-in-difference calculation.

Cross-sectional study for the clinical application of extracorporeal membrane oxygenation in Mainland China, 2018

Background

To investigate the epidemiology and in-hospital mortality of veno-venous (VV) and veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) in Mainland China throughout 2018.

Methods

Patients supported by ECMO from 1700 tertiary hospitals in 31 provinces from January 1 to December 31, 2018, were selected from the National Clinical Improvement System database.

Results

The 1700 included hospitals had 2073 cases of ECMO in 2018, including 714 VV and 1359 VA ECMOs. The average patient age was 50 years (IQR 31–63), and 1346 were male. The average hospital stay was 17 days (IQR 7–30), and the average costs per case was $36,334 (IQR 22,547–56,714). The three provinces with the highest number of ECMO cases were Guangdong, Beijing, and Zhejiang; the southeast coastal areas and regions with higher GDP levels had more cases. Overall in-hospital mortality was 29.6%. Mortality was higher among patients who were male, over 70 years old, living in underdeveloped areas, and who were treated during the summer. Mortality in provinces with more ECMO cases was relatively low. The co-existence of congenital malformations, blood system abnormalities, or nervous system abnormalities increased in-hospital mortality.

Conclusions

Mortality and medical expenses of ECMO among patients in China were relatively low, but large regional and seasonal differences were present. Risk factors for higher in-hospital mortality were older age, male sex, in underdeveloped areas, and treatment during the summer. Additionally, congenital malformations and blood system and nervous system abnormalities were associated with in-hospital mortality.

Seasonal variation in U.S. hospitalizations for chronic limb-threatening ischemia

BACKGROUND

Seasonal variation in coronary artery disease is well described, with a peak in the winter and a trough in the summer. However, little is known about seasonal trends in hospital admission for critical limb-threatening ischemia (CLTI) and associated outcomes.

METHODS

Patients admitted with CLTI from January 1, 2012 through August 31, 2015 were identified in the Healthcare Cost and Utilization Project's National Inpatient Sample based upon administrative claims diagnosis codes. The primary outcome was seasonal hospitalization incidence, and secondary outcomes included mortality rates and rates of in-hospital major and minor amputations among nondiabetics and diabetics.

RESULTS

Of 1,276,745 hospitalizations for CLTI during the study period, 28.3% occurred in the spring, the peak admission season, and 19.1% occurred in the fall, the nadir. In-hospital mortality was highest during the winter (adjusted odds ratio [OR]: 1.08; 95% confidence interval [CI]: 1.03-1.14), and followed the highest seasonal rates of influenza in the fall; however, other important comorbidities did not differ significantly by season. For the overall cohort, there was no significant seasonal variation in rates of major or minor amputation, although seasonal rates were different according to diabetic status. Patients without diabetes had the highest odds of amputation in the spring (OR 1.07; 95% CI: 1.02-1.12), although this trend was not identified among patients with diabetes.

CONCLUSIONS

There is significant seasonal variability in CLTI admissions and mortality but minimal variability in amputation rates. Understanding the seasonal variation in CLTI may help to identify individuals at greatest risk for hospitalization and death through patient and provider education efforts.

Acute Myocardial Infarction among Young Adult Men in a Region with Warm Climate: Clinical Characteristics and Seasonal Distribution

The aim of this cross sectional study was to investigate the influence of the seasons on acute myocardial infarction (AMI) among young adult among young adults aged <45 years compared to old adults aged ≥45 years. The seasonal distribution of AMI hospital admissions among young adult men in eastern Taiwan was assessed. Data were extracted from 1413 male AMI patients from January 1994 to December 2015, including onset date, the average temperature (Tave) on the date of AMI hospitalization (AMI-Tave), and conventional risk factors, notably smoking, diabetes, hypertension, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and body mass index (BMI). The 1413 cases were divided into two groups: the young group (n = 138, <45 y/o) and the older group (n = 1275, ≥45 y/o). The differences between groups were examined. Logistic regression analyses were used to evaluate the associations between the seasons and the AMI hospitalization among the young group. The young group showed significantly higher percentage of smokers, BMI, total cholesterol levels, and triglycerides levels but lower percentage of diabetes and hypertension than the older group (p < 0.05). AMI hospitalization in winter was significantly greater compared to the other seasons among the young group (p < 0.05). Winter hospitalization was significantly associated with the young group relative to the older group (adjusted OR 1.750; 95% CI 1.151 to 2.259), while winter AMI-Tave in the young group was similar to that in the older group. Young adult men diagnosed with AMI are more likely than older adult men to be smokers, obese, and show an onset dependent on winter but not low-temperature in a region with a warm climate.

Chronobiological patterns of acute aortic dissection in central China

BACKGROUND

Acute aortic dissection (AAD) is a life-threatening emergency with poor clinical outcomes. Understanding the chronological patterns of AAD onset would be helpful for identifying the triggers of AAD and preventing this catastrophic event.

METHODS

We collected data from 2048 patients diagnosed with AAD at Tongji Hospital (Wuhan, China) from 2011 to 2018. The χ2 test was used to determine whether a specific period had significantly different seasonal/weekly distributions from other periods. Fourier models were used to analyse the rhythmicity in monthly/circadian distribution.

RESULTS

The mean age was 53.4±10.9 years, and 1161 patients (56.7%) were under 55 years. One thousand six hundred fifty-seven patients (80.9%) were male, and 935 cases (45.7%) were type A dissections. The proportions of patients with comorbid hypertension/diabetes were 60.3% (1234 cases) and 1.8% (36 cases), respectively. A peak was identified in colder periods (winter/December) and a trough in warmer periods (summer/June). No significant variation was observed in weekly distribution. Fourier analysis showed a statistically significant circadian variation (p<0.001) with a nocturnal trough in 2:00-3:00, a morning peak in 9:00-10:00, and an afternoon peak in 16:00-17:00. Subgroup analyses identified circadian rhythmicity in all subgroups except for the female group and younger group (younger than 55 years).

CONCLUSION

Our results confirmed that the onset of AAD exhibits significant seasonal, monthly and circadian patterns. Patients with AAD with different Stanford-type dissections, sexes, ages and hypertension statuses could present different circadian variations. These findings may provide novel perspectives for identifying the triggers of AAD and better preventing this catastrophic event.

Seasonal Variations in the Pathogenesis of Acute Coronary Syndromes

Background Seasonal variations in acute coronary syndromes (ACS) have been reported, with incidence and mortality peaking in the winter. However, the underlying pathophysiology for these variations remain speculative. Methods and Results Patients with ACS who underwent optical coherence tomography were recruited from 6 countries. The prevalence of the 3 most common pathologies (plaque rupture, plaque erosion, and calcified plaque) were compared between the 4 seasons. In 1113 patients with ACS (885 male; mean age, 65.8±11.6 years), the rates of plaque rupture, plaque erosion, and calcified plaque were 50%, 39%, and 11% in spring; 44%, 43%, and 13% in summer; 49%, 39%, and 12% in autumn; and 57%, 30%, and 13% in winter (P=0.039). After adjusting for age, sex, and other coronary risk factors, winter was significantly associated with increased risk of plaque rupture (odds ratio [OR], 1.652; 95% CI, 1.157-2.359; P=0.006) and decreased risk of plaque erosion (OR, 0.623; 95% CI, 0.429-0.905; P=0.013), compared with summer as a reference. Among patients with rupture, the prevalence of hypertension was significantly higher in winter (P=0.010), whereas no significant difference was observed in the other 2 groups. Conclusions Seasonal variations in the incidence of ACS reflect differences in the underlying pathobiology. The proportion of plaque rupture is highest in winter, whereas that of plaque erosion is highest in summer. A different approach may be needed for the prevention and treatment of ACS depending on the season of its occurrence. Registration URL: https://www.clini​caltr​ials.gov. Unique identifier: NCT03479723.

Ambient temperature, seasonal influenza and risk of cardiovascular disease in a subtropical area in Southern China

BACKGROUND

Given the regular winter recurrence of influenza epidemics and the biologically plausible association between seasonal influenza and cardiovascular events, researchers assumed a valid and reliable influenza forecast could envision the timing and burden of winter surge in cardiovascular (CVD) hospitalizations. This, however, is well justified only in temperate regions. In this study, we aim to investigate the temporal association between ambient temperature, seasonal influenza and risk of cardiovascular events in a subtropical city.

METHODS

Generalized additive model was used in conjunction with distributed-lag non-linear model of quasi-Poisson family to estimate the association of interest with daily CVD admissions as outcome and daily influenza admissions as predictor, while controlling for meteorological factors (i.e. temperature, relative humidity, wind speed and total rainfall) and respiratory pollutants (i.e. nitrogen dioxide, sulphur dioxide, ozone and PM₁₀). Results were expressed in the form of relative risk (RR).

RESULTS

Using median as the reference value, a U-shaped association was observed between CVD admissions and temperature. A slight decrease in RR was detected mainly towards the lower end of the temperature scale after adjusting for influenza admissions. Risk of CVD admission was found to be positively associated with the number of influenza hospitalization cases; this association remained consistent and statistically significant across subgroups of age except for those aged 5-49 years.

CONCLUSION

The slight reduction in CVD admission risk towards the lower end of the temperature scale after controlling for influenza activity might be attributed to the winter peaks of influenza, meaning that the effect of low temperature on CVD admissions might be partly mediated by influenza infection. In summary, this study reassures us that ambient temperature is independently associated with CVD hospital admissions and offers support for a positive association between seasonal influenza activity and cardiovascular events in Hong Kong.

Temporal trends of the association between ambient temperature and hospitalisations for cardiovascular diseases in Queensland, Australia from 1995 to 2016: A time-stratified case-crossover study

BACKGROUND

In the context of global warming, studies have turned to assess the temporal trend of the association between temperature and health outcomes, which can be used to reflect whether human beings have adapted to the local temperature. However, most studies have only focused on hot temperature and mortality. We aim to investigate the temporal variations in the association between ambient temperature and hospitalisations for cardiovascular diseases in Queensland, Australia from 1995 to 2016.

METHODS AND FINDINGS

We obtained data on 1,855,717 cardiovascular hospitalisations (mean age: 65.9 years, 42.7% female) from all 443 postal areas in Queensland, Australia between January 1, 1995 and December 31, 2016. Grid-level meteorological data were downloaded from scientific information for landowners. We used a time-stratified case-crossover design fitted with a conditional quasi-Poisson regression model and time-varying distributed lag nonlinear model (DLNM) to evaluate the association between temperature and cardiovascular hospitalisations and the temporal trends of the associations. Stratified analyses were performed in different age, sex, and climate zones. In all groups, relative risks (RRs) of cardiovascular hospitalisations associated with high temperatures (heat effects) increased, but cold effects showed a decreasing trend from 1995 to 2016. The increasing magnitude of heat effects was larger (p = 0.002) in men than in women and larger (p < 0.001) in people aged ≤69 years than in those aged ≥70 years. There was no apparent difference amongst different climate zones. The study was limited by the switch from ICD-9 to ICD-10 coding systems, by being unable to separate first-time hospitalisation from repeated hospitalisations, and possibly by confounding by air pollution or by influenza infections.

CONCLUSION

The impacts of cold temperatures on cardiovascular hospitalisations have decreased, but the impacts of high temperatures have increased in Queensland, Australia. The findings highlight that Queensland people have adapted to the impacts of cold temperatures, but not high temperatures. The burden of cardiovascular hospitalisations due to high temperatures is likely to increase in the context of global warming.

Association between ambient temperature and hypertensive disorders in pregnancy in China

Hypertensive disorders in pregnancy (HDPs) are leading perinatal diseases. Using a national cohort of 2,043,182 pregnant women in China, we evaluated the association between ambient temperatures and HDP subgroups, including preeclampsia or eclampsia, gestational hypertension, and superimposed preeclampsia. Under extreme temperatures, very cold exposure during preconception (12 weeks) increases odds of preeclampsia or eclampsia and gestational hypertension. Compared to preconception, in the first half of pregnancy, the impact of temperature on preeclampsia or eclampsia and gestational hypertension is opposite. Cold exposure decreases the odds, whereas hot exposure increases the odds. Under average temperatures, a temperature increase during preconception decreases the risk of preeclampsia or eclampsia and gestational hypertension. However, in the first half of pregnancy, temperature is positively associated with a higher risk. No significant association is observed between temperature and superimposed preeclampsia. Here we report a close relationship exists between ambient temperature and preeclampsia or eclampsia and gestational hypertension.

Hypertensive disorders in pregnancy are prevalent perinatal diseases. Here the authors report an association between ambient temperature before or after conception and risk of preeclampsia or eclampsia and gestational hypertension.

No 'Christmas holiday effect' in Australia for cardiovascular and stroke mortality

OBJECTIVES

Cardiovascular events and mortality have shown a higher incidence within the Christmas holiday period in previous studies and in the northern and southern hemisphere. Our study aimed to assess changes in cardiovascular and stroke mortality variation around the Christmas period in Australia.

STUDY DESIGN

The study design is a population-based case-control study.

METHODS

Daily mortality data attributed to stroke and cardiovascular was compiled from Australia between 1989 and 2015, amounting to approximately 700,000 and 250,000 deaths, respectively. A locally weighted polynomial regression line was used to estimate expected mortality rates during that period and compared with actual results.

RESULTS

There was a non-significant increase of 1.08% (P = 0.35) and 0.20% (P = 0.87) for coronary heart disease and stroke mortality, respectively, in the Christmas holiday period.

CONCLUSIONS

There is no evidence of an increase in cardiovascular and stroke mortality in the Christmas holiday period in Australia.

Higher admission rates and in-hospital mortality for acute type A aortic dissection during Influenza season: a single center experience

Triggering events for acute aortic dissections are incompletely understood. We sought to investigate whether there is an association between admission for acute type A aortic dissection (ATAAD) to the University of Michigan Medical Center and the reported annual influenza activity by the Michigan Department of Health and Human Services. From 1996–2019 we had 758 patients admitted for ATAAD with 3.1 admissions per month during November-March and 2.5 admissions per month during April-October (p = 0.01). Influenza reporting data by the Michigan Department of Health and Human Services became available in 2009. ATAAD admissions for the period 2009–2019 (n = 455) were 4.8 cases/month during peak influenza months compared to 3.5 cases/month during non-peak influenza months (p = 0.001). ATAAD patients admitted during influenza season had increased in-hospital mortality (11.0% vs. 5.8%, p = 0.024) and increased 30-day mortality (9.7 vs. 5.4%, p = 0.048). The results point to higher admission rates for ATAAD during months with above average influenza rates. Future studies need to investigate whether influenza virus infection affects susceptibility for aortic dissection, and whether this risk can be attenuated with the annual influenza vaccine in this patient population.

Diversity of and initiatives for hypertension management in Asia-Why we need the HOPE Asia Network

The Hypertension Cardiovascular Outcome Prevention and Evidence in Asia (HOPE Asia) Network was set up to improve the management of hypertension in Asia with the ultimate goal of achieving "zero" cardiovascular events. Asia is a diverse continent, and the prevalence of hypertension has increased over the last 30 years. There are a number of Asia-specific features of hypertension and hypertension-related cardiovascular complications, which means that a region-specific approach is needed. White-coat hypertension will become more of an issue over time as Asian populations age, and masked hypertension is more prevalent in Asian than in Western countries. Identifying and treating masked hypertension is important to reduce cardiovascular risk. Abnormal patterns of blood pressure (BP) variability common in Asia include exaggerated early morning BP surge and nocturnal hypertension. These are also important cardiovascular risk factors that need to be managed. Home blood pressure monitoring (HBPM) is an important tool for detecting white-coat and masked hypertension, and monitoring BP variability, and practices in Asia are variable. Use of HBPM is important given the Asia-specific features of hypertension, and strategies are needed to improve and standardize HBPM usage. Development of HBPM devices capable of measuring nocturnal BP along with other information and communication technology-based strategies are key developments in the widespread implementation of anticipation medicine strategies to detect and prevent cardiovascular events in patients with hypertension. Region-wide differences in hypertension prevalence, control, and management practices in Asia highlight the importance of information sharing to facilitate best practices.

Occurrence of fatal infective endocarditis: a population-based study in Finland

Background

Infective endocarditis (IE) is a serious mainly bacterial infection associated with high mortality. Epidemiology of fatal IE is however largely unknown. We studied occurrence and trends of fatal IE in a population-based setting.

Methods

All adults (≥18 years of age) who deceased due to IE in Finland during 2004–2016 were studied. Data was collected from the nationwide, obligatory Cause of Death Registry. Background population consisted of 28,657,870 person-years and 651,556 deaths.

Results

Infective endocarditis contributed to death in 754 cases and was the underlying cause of death in 352 cases. The standardized incidence rate of deaths associated with IE was 1.42 (95% confidence interval (CI): 1.32–1.52) per 100,000 person-years. Incidence rate increased progressively with aging from 50 years of age. Men had a two-fold risk of acquiring fatal infective endocarditis compared to women (risk ratio (RR) 1.95; 95% CI: 1.71–2.22; P < 0.0001). On average, IE contributed to 1.16 (95% CI: 1.08–1.24) out of 1000 deaths in general adult population. The proportionate amount of deaths with IE was highest in population aged < 40 years followed by gradual decrease with aging. Incidence rate and proportion of deaths caused by IE remained stable during the study period.

Conclusions

Our study describes for the first time the population-based epidemiology of fatal IE in adults. Men had a two-fold risk of acquiring fatal IE compared to women. Although occurrence of fatal IE increased with aging, the proportion of deaths to which IE contributed was highest in young adult population.

A Case-Crossover Study to Investigate the Effects of Atmospheric Particulate Matter Concentrations, Season, and Air Temperature on Accident and Emergency Presentations for Cardiovascular Events in Northern Italy

Atmospheric particulate matter (PM) has multiple adverse effects on human health, high temperatures are also associated with adverse health outcomes, and the frequency of cardiovascular events (CVEs) varies with season. We investigated a hypothesized increase in PM-related accident and emergency (A&E) presentations for CVE with high temperature, warm season, days of high influenza incidence, and in people with a cancer diagnosis, using a time-stratified case-crossover study design. Outcomes were associations of A&E presentation for CVE with atmospheric PM ≤ 10 μm (PM₁₀), season, and air temperature. PM₁₀ levels in the municipality of residence (exposure variable) were estimated by modeling data from local monitoring stations. Conditional logistic regression models estimated odds ratios (OR) with 95% confidence intervals (CI) for presentations in relation to supposed influencers, adjusting for confounders. Study participants were all who presented at the A&E of a large hospital near Milan, Italy, for a CVE (ICD-9: 390–459) from 1st January 2014 to 31st December 2015. There were 1349 A&E presentations for CVE in 2014–2015 and 5390 control days. Risk of A&E presentation was significantly increased on hot days with OR 1.34 (95%CI 1.05–1.71) per 10 μg/m³ PM₁₀ increment (as mean PM₁₀ on day of presentation, and 1 and 2 days before (lags 0–2)), and (for lag 0) in autumn (OR 1.23, 95%CI 1.09–1.37) and winter (OR 1.18, 95%CI 1.01–1.38). Risks were also significantly increased when PM₁₀ was on lag 1, in people with a cancer diagnosis in the spring and summer months (1.88, 95%CI 1.05–3.37), and on days (lags 0–2) of high influenza incidence (OR 2.34, 95%CI 1.01–5.43). PM₁₀ levels exceeded the 50 μg/m³ “safe” threshold recommended by the WHO and Italian legislation for only 3.8% of days during the warm periods of 2014–2015. Greater risk of A&E presentation for CVE in periods of high PM₁₀ and high temperature suggests that “safe” thresholds for PM₁₀ should be temperature-dependent and that the adverse effects of PM₁₀ will increase as temperatures increase due to climate change.

Seasonality of acute kidney injury incidence and mortality among hospitalized patients

Background

Understanding disease seasonality is important for improving clinical practice, hospital resource utilization and community-based preventive care. However, no studies have investigated the seasonality of acute kidney injury (AKI).

Methods

In the Tokushukai Medical Database, which includes 38 Japanese community hospitals, we identified hospitalized patients with AKI based on the Kidney Disease: Improving Global Outcomes serum creatinine criteria from January 2012 to December 2014. We plotted the number and proportion of patients with AKI among hospitalized patients by month of hospital admission. Subgroup analyses were conducted by the admission diagnosis category, timing of AKI diagnosis and age. We also examined the association between month of hospital admission and AKI, adjusting for patient characteristics and AKI risk factors. Finally, we assessed seasonal variations in disease severity and 30-day mortality of patients with AKI.

Results

We identified 81 279 (14.6%) patients with AKI among 555 940 hospitalized patients. The proportion of patients with AKI was highest in January (16.7%) and lowest in June (13.4%). Subgroup analyses suggested that the seasonality of AKI incidence was driven by community-acquired AKI associated with the admission diagnosis of cardiovascular and pulmonary diseases among older patients. The adjusted odds ratio for AKI (January versus June) was 1.24 (95% confidence interval, 1.17-1.31). Patients with AKI showed a larger number of failing organs in winter, and their 30-day mortality was 16.4% in spring, 14.5% in summer, 15.6% in autumn and 18.4% in winter.

Conclusion

AKI is more common among hospitalized patients and patients with AKI are more severely ill in winter.

Atmospheric fronts as minor cardiovascular risk factors, a new approach to preventive cardiology

BACKGROUND

Cardiovascular diseases are the number one cause of death globally and represent 31% of all global deaths. The aim of our study was to determine the influence of front effects on acute cardiovascular diseases (ACVDs).

METHODS

We obtained all ACVD admissions in a Central-European region, Hungary, Budapest. A time-series analysis was applied to 6499 morbidity cases during a five-year period (2009-2013). Poisson-regression model was used and adjusted for air temperature, pressure, humidity, wind velocity, their interactions and seasonality to assess the association of fronts and ACVDs.

RESULTS

There is a positive significant association between ACVDs and a cold front effect lagged by one day (p=0.018) with a relative risk (RR) of 1.095 [95% CI (1.021,1.181)]. Our findings show that among patient subgroups with major cardiovascular risk factors (hypertension, diabetes, hyperlipidemia, history of CVDs) the patterns are similar, but occluded fronts also have a significant effect.

CONCLUSION

Atmospheric fronts could play an important role in the pathogenesis of ACVDs. Our findings might help to provide a better understanding about fronts as minor cardiovascular risk factors and to organize medical prevention more effectively. Our research project may become a basis of a new field of preventive cardiovascular medicine in the future.

Heat Stress Impacts on Cardiac Mortality in Nepali Migrant Workers in Qatar

Background: Qatar is a major destination country for Nepali migrant workers (NMWs; main age range 25–35 years) in the construction trade. These 120,000+ NMWs are exposed to various occupational hazards, including excessive heat, and 3–4 workers die each week. Our study aimed to show whether heat exposure caused deaths. Methods: The worker population and mortality data of NMWs were retrieved from government institutions in Nepal. Heat exposure was assessed by monthly estimates of daily wet bulb globe temperature (WBGT), for in-shade conditions, from data collected at the Doha weather station from 2009 to 2017. Working in the sun during the middle of the day would add 2–3°C to the in-shade WBGT values. Daily deaths and their causes were obtained from the records of the Foreign Employment Promotion Board (FEPB) in Nepal, 2009–2017. Interviews with returning NMWs about their working conditions and the impacts of these conditions added information. The association between the heat variable and mortality was tested with standard statistical methods. Results: The average annual death rate for NMWs in Qatar was 150 deaths/100,000. According to interviews, the majority of NMWs were found working in high WBGT (>31°C) each working day during hot months. The major cause of these deaths was recorded as cardiovascular problems (cardiovascular disease; CVD). Unfortunately, the causes of death were poorly described, and many deaths were listed as “cardiac arrest.” We included these deaths in the broader category of “cardiovascular causes.” There was a strong correlation between average monthly afternoon heat levels (WBGT) and CVD mortality. It is likely that a large proportion of these CVD deaths during hot months were due to serious heat stroke. Global studies show that approximately 15% of deaths in the age group 25–35 years are due to CVD causes. However, in this NMW population, the figures were 22% during the cool season and 58% during the hot season. Conclusions: The increased CVD mortality during hot periods is most likely due to severe heat stress. As many as 200 of the 571 CVD deaths during 2009–2017 could have been prevented if effective heat protection had been implemented as a part of local occupational health and safety programs. There is an urgent need for protection against such heat effects among NMWs, and rising temperatures from ongoing climate change are further increasing the health risks. Cause of death records for workers dying in hot conditions should be more precise than “cardiac arrest.”

Lack of seasonality in occurrence of pericarditis, myocarditis, and endocarditis

PURPOSE

The etiology of pericarditis, myocarditis, and endocarditis is predominantly infectious, and infections often show seasonal variation. Little is known, however, about seasonal patterns in these cardiopathies.

METHODS

Using Danish health care registries, we identified all patients with a first-time hospital-based diagnosis of pericarditis, myocarditis, or endocarditis between 1994 and 2016. We estimated peak-to-trough ratios from fitted sine curves to measure the intensity of seasonal variation in occurrence during the study period. Because randomness will lead to small apparent seasonal patterns, we also conducted a plasmode simulation to assess the degree of seasonality that randomness would produce.

RESULTS

Crude peak-to-trough ratios of monthly frequencies summarized over a year were small. We estimated a peak-to-trough ratio of 1.10 (95% confidence interval [CI], 1.05-1.14) for pericarditis, 1.11 (95% CI, 1.02-1.21) for myocarditis, and 1.01 (95% CI, 1.00-1.07) for endocarditis. The simulated mean peak-to-trough ratios found after randomly reassigning the monthly frequencies within each year were 1.04 (95% CI, 1.00-1.09) for pericarditis, 1.04 (95% CI, 1.00-1.13) for myocarditis, and 1.04 (95% CI, 1.00-1.10), for endocarditis.

CONCLUSION

The data indicate no important seasonal variation in the occurrence of pericarditis, myocarditis, and endocarditis in Denmark between 1994 and 2016.

Venous Thromboembolism in Denmark: Seasonality in Occurrence and Mortality

Background  Many cardiovascular conditions exhibit seasonality in occurrence and mortality, but little is known about the seasonality of venous thromboembolism.

Methods  Using Danish registries, we identified all patients with deep vein thrombosis, pulmonary embolism, splanchnic vein thrombosis, cerebral vein thrombosis, and retinal vein thrombosis during 1977–2016. We tallied monthly deaths occurring within 90 days of the venous thromboembolism diagnosis. We estimated peak-to-trough ratios and timing of the peak of both diagnoses and deaths summed over all years of the study period. The departure from 1.0 of the peak-to-trough ratio measures the intensity of any seasonal pattern.

Results  We estimated a peak-to-trough ratio of 1.09 (95% confidence interval: 1.07–1.11) for deep vein thrombosis and 1.22 (1.19–1.24) for pulmonary embolism occurrence. The peak-to-trough ratios for splanchnic vein thrombosis, cerebral vein thrombosis, and retinal vein thrombosis occurrence were 1.10 (1.01–1.20), 1.19 (1.00–1.40), and 1.12 (1.07–1.17), respectively. The occurrence of all conditions peaked during winter or fall. In time trend analyses, the peak-to-trough ratio increased considerably for splanchnic vein thrombosis, cerebral vein thrombosis, and retinal vein thrombosis occurrence. In associated mortality, the peak-to-trough ratio for deep vein thrombosis was larger (1.15, 1.07–1.23) than that for pulmonary embolism (1.04, 1.01–1.08).

Discussion  Excess winter risks were modest, but more marked for pulmonary embolism occurrence than for deep vein thrombosis occurrence. The seasonal pattern intensified throughout the study period for splanchnic vein thrombosis, cerebral vein thrombosis, and retinal vein thrombosis. The winter peak in mortality following pulmonary embolism was smaller than that for deep vein thrombosis.

Weather fluctuations: predictive factors in the prevalence of acute coronary syndrome

Background: Meteorological parameters and seasonal changes can play an important role in the occurrence of acute coronary syndrome (ACS). However, there is almost no evidence on a national level to suggest the associations between these variables and ACS in Iran. We aim to identify the meteorological parameters and seasonal changes in relationship to ACS.

Methods: This retrospective cross-sectional study was conducted between 03/19/2015 to 03/18/2016 and used documents and records of patients with ACS in Mazandaran ProvinceHeart Center, Iran. The following definitive diagnostic criteria for ACS were used: (1) existence of cardiac enzymes (CK or CK-MB) above the normal range; (2) Greater than 1 mm ST-segment elevation or depression; (3) abnormal Q waves; and (4) manifestation of troponin enzyme in the blood. Data were collected daily, such as temperature (Celsius) changes, wind speed and its direction, rainfall, daily evaporation rate; number of sunny days, and relative humidity were provided by the Meteorological Organization of Iran.

Results: A sample of 2,054 patients with ACS were recruited. The results indicated the highest ACS events from March to May. Generally, wind speed (18 PM) [IRR = 1.051 (95% CI: 1.019 to1.083), P=0.001], daily evaporation [IRR = 1.039 (95% CI: 1.003 to 1.077), P=0.032], daily maximum (P<0.001) and minimum (P=0.003) relative humidity was positively correlated withACS events. Also, negatively correlated variables were daily relative humidity (18 PM) [IRR =0.985 (95% CI: 0.978 to 0.992), P<0.001], and daily minimum temperature [IRR = 0.942 (95%CI: 0.927 to 0.958), P<0.001].

Conclusion: Climate changes were found to be significantly associated with ACS; especially from cold weather to hot weather in March, April and May. Further research is needed to fully understand the specific conditions and cold exposures.

Winter Peaks in Heart Failure: An Inevitable or Preventable Consequence of Seasonal Vulnerability?

Climate change is a major contributor to annual winter peaks in cardiovascular events across the globe. However, given the paradoxical observation that cardiovascular seasonality is observed in relatively mild as well as cold climates, global warming may not be as positive for the syndrome of heart failure (HF) as some predict. In this article, we present our Model of Seasonal Flexibility to explain the spectrum of individual responses to climatic conditions. We have identified distinctive phenotypes of resilience and vulnerability to explain why winter peaks in HF occur. Moreover, we identify how better identification of climatic vulnerability and the use of multifaceted interventions focusing on modifiable bio-behavioural factors may improve HF outcomes.

Seasonal variation in physical activity in patients with heart failure

BACKGROUND AND OBJECTIVES

Physical activity is important for all heart failure (HF) patients to improve quality of life and physical function. Since adherence to physical activity is low and could differ between seasons, it is essential to explore factors related to change that may depend on seasonal changes. The purpose of this study was to describe the seasonal differences in physical activity and assess factors that influence these differences in a country with markedly different winter-to-summer weather conditions (in temperature, hours of daylight and snow fall).

METHODS

The study had a cross-sectional survey design. Outpatients with HF completed a questionnaire on physical activity, motivation and self-efficacy to exercise and HF symptom severity in the summer and the winter in a northern hemisphere country. We used analysis of variance to evaluate seasonal differences in physical activity, motivation, self-efficacy and HF symptom severity.

RESULTS

Eighty-seven patients with HF (29% women, mean age 70 ± 9 years) were included and 35% performed less physical activity (METs) in the winter, compared to the summer. Increased symptom severity during the winter was associated with lower activity levels.

CONCLUSION

One-third of the patients performed less physical activity during the winter compared to the summer, and this was associated with symptom severity. Decreased physical activity was not related with motivation and self-efficacy. This study emphasises the need for personalised physical activity programmes that also assess symptom severity and change in symptom severity depending between seasons.

Long-term exposure to ambient fine particulate matter and incidence of diabetes in China: A cohort study

BACKGROUND

Diabetes caused substantial economic and health burden worldwide. However, the associations between air pollution and diabetes incidence were rarely reported in the developing countries, especially in China with relatively high PM_2.5 concentrations.

OBJECTIVES

A cohort-based study was conducted to assess the diabetes incidence associated with long-term exposure to ambient PM_2.5.

METHODS

We collected individual health data and risk factors from the project of Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR Project) from 15 provinces over China. Diabetes was defined as fasting glucose levels ≥7.0 mmol/L at the follow-ups and/or the use of insulin or oral hypoglycemic agents and/or diagnosed medical history of diabetes during 2004 to 2015. Individual-level PM_2.5 exposures were estimated from satellite-based PM_2.5 concentrations (10 km spatial resolution) during the study period. Cox proportional hazards models with random intercepts of each cohort and region were employed to estimate the diabetes incidence attributable to PM_2.5, after the adjustment for age, gender, body mass index, smoking status, education, work-related physical activity level, hypertension, urbanicity, county-level averaged years of education, and long-term levels of temperature and relative humidity.

RESULTS

A total of 88,397 subjects were analyzed with 580,928 person-years of follow-up after 2004, among which 6439 new cases of diabetes were observed. The mean age of the subjects was 51.7 years at baseline. For an increase of 10 μg/m³ in long-term PM_2.5 exposure, the multivariable-adjusted percent increase in the diabetes incidence was estimated to be 15.66% (95% confidence interval: 6.42%, 25.70%). The adverse effects of PM_2.5 were larger among females, rural subjects, non-smokers, normotensives, subjects younger than 65 years and subjects with body mass index <25 kg/m².

CONCLUSIONS

Our findings provided evidence for the association of long-term exposure to PM_2.5 with diabetes incidence in China. A sustained improvement of air quality will benefit the reduction for diabetes epidemic in China.

Seasonality in Mortality in a Cardiology Department: A Five-Year Analysis in 500 Patients

BACKGROUND

Previous studies have indicated that cardiovascular mortality follows a seasonal trend. The aim of this work was to determine the evolution of mortality throughout the year in a cardiology department.

METHODS

All admissions and deaths occurring in our Cardiology Department over a 5-year period (2013-2017) were recorded retrospectively.

RESULTS

From a total of 17,829 hospital admissions, 500 patients died (2.8%, 0.3 patients/day). The mean age of deceased patients was 74.2 ± 13.1 years, and 186 (37.2%) were women. Mortality ranged from 0.17 deaths/day in August to 0.40 deaths/day in February (p = 0.03), and from 0.20 deaths/day in summer to 0.36 deaths/day in winter (p = 0.001). There was also a trend towards a variation in hospitalizations, with a peak in January (10.5 admissions/day) and the lowest figure in August (7.0 admissions/day), p = 0.047. We found no significant seasonal trend regarding mortality rate with respect to the number of hospital admissions (p = 0.89). The most common cause of death was refractory heart failure (267 patients [65.8%]). A noncardiac cause of death was observed in 134 patients (26.8%).

CONCLUSIONS

In a cardiology department, there are twice as many deaths in winter as in summer. Hospitalizations also tend to be more frequent in winter than in summer.

Music-Enhanced Analgesia and Antiseizure Activities in Animal Models of Pain and Epilepsy: Toward Preclinical Studies Supporting Development of Digital Therapeutics and Their Combinations With Pharmaceutical Drugs

Digital therapeutics (software as a medical device) and mobile health (mHealth) technologies offer a means to deliver behavioral, psychosocial, disease self-management and music-based interventions to improve therapy outcomes for chronic diseases, including pain and epilepsy. To explore new translational opportunities in developing digital therapeutics for neurological disorders, and their integration with pharmacotherapies, we examined analgesic and antiseizure effects of specific musical compositions in mouse models of pain and epilepsy. The music playlist was created based on the modular progression of Mozart compositions for which reduction of seizures and epileptiform discharges were previously reported in people with epilepsy. Our results indicated that music-treated mice exhibited significant analgesia and reduction of paw edema in the carrageenan model of inflammatory pain. Among analgesic drugs tested (ibuprofen, cannabidiol (CBD), levetiracetam, and the galanin analog NAX 5055), music intervention significantly decreased paw withdrawal latency difference in ibuprofen-treated mice and reduced paw edema in combination with CBD or NAX 5055. To the best of our knowledge, this is the first animal study on music-enhanced antinociceptive activity of analgesic drugs. In the plantar incision model of surgical pain, music-pretreated mice had significant reduction of mechanical allodynia. In the corneal kindling model of epilepsy, the cumulative seizure burden following kindling acquisition was lower in animals exposed to music. The music-treated group also exhibited significantly improved survival, warranting further research on music interventions for preventing Sudden Unexpected Death in Epilepsy (SUDEP). We propose a working model of how musical elements such as rhythm, sequences, phrases and punctuation found in K.448 and K.545 may exert responses via parasympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis. Based on our findings, we discuss: (1) how enriched environment (EE) can serve as a preclinical surrogate for testing combinations of non-pharmacological modalities and drugs for the treatment of pain and other chronic diseases, and (2) a new paradigm for preclinical and clinical development of therapies leading to drug-device combination products for neurological disorders, depression and cancer. In summary, our present results encourage translational research on integrating non-pharmacological and pharmacological interventions for pain and epilepsy using digital therapeutics.

Prevalence and profile of "seasonal frequent flyers" with chronic heart disease: Analysis of 1598 patients and 4588 patient-years follow-up

BACKGROUND

Peaks and troughs in cardiovascular events correlated with seasonal change is well established from an epidemiological perspective but not a clinical one.

METHODS

Retrospective analysis of the recruitment, baseline characteristics and outcomes during minimum 12-month exposure to all four seasons in 1598 disease-management trial patients hospitalised with chronic heart disease. Seasonality was prospectively defined as ≥4 hospitalisations (all-cause) AND >45% of related bed-days occurring in any one season during median 988 (IQR 653, 1394) days follow-up.

RESULTS

Patients (39% female) were aged 70 ± 12 years and had a combination of coronary artery disease (58%), heart failure (54%), atrial fibrillation (50%) and multimorbidity. Overall, 29.9% of patients displayed a pattern of seasonality. Independent correlates of seasonality were female gender (adjusted OR 1.27, 95% CI 1.01-1.61; p = 0.042), mild cognitive impairment (adjusted OR 1.51, 95% CI 1.16-1.97; p = 0.002), greater multimorbidity (OR 1.20, 95% CI 1.15-1.26 per Charlson Comorbidity Index Score; p < 0.001), higher systolic (OR 1.01, 95%CI 1.00-1.01 per 1 mmHg; p = 0.002) and lower diastolic (OR 0.99, 95% CI 0.98-1.00 per 1 mmHg; p = 0.002) blood pressure. These patients were more than two-fold more likely to die (adjusted HR 2.16, 95% CI 1.60-2.90; p < 0.001) with the highest and lowest number of deaths occurring during spring (31.7%) and summer (19.9%), respectively.

CONCLUSIONS

Despite high quality care and regardless of their diagnosis, we identified a significant proportion of "seasonal frequent flyers" with concurrent poor survival in this real-world cohort of patients with chronic heart disease.

ECMO use and mortality in adult patients with cardiogenic shock: a retrospective observational study in U.S. hospitals

Background

Extracorporeal membrane oxygenation (ECMO) is increasingly used in resuscitation of critically ill patients with documented improved survival. Few studies describe ECMO use in cardiogenic shock. This study examines ECMO use and identifies variables associated with mortality in patients treated for cardiogenic shock in US hospitals.

Methods

A retrospective observational study of the US Nationwide Emergency Department Sample (NEDS) database of 2013 was conducted. Weighted visits for cardiogenic shock (discharge diagnosis) with ECMO use were included. Collected data was analyzed and variables associated with mortality were identified.

Results

A total of 922 weighted patients with cardiogenic shock and ECMO were included. Mean age was 50.8 years. They were more commonly males (66.3%; n = 658). Slightly over half (51.0%, n = 506) survived to hospital discharge. Mean charges per patient were $589,610.5. Mean length of stay was 21.8 days.

Increased mortality was associated with presence of respiratory diseases (OR = 3.83), genitourinary diseases (OR = 4.97), undergoing an echocardiogram (OR = 4.63), and presenting during seasons other than Fall. Lower mortality was noted in patients with injury and poisoning (OR = 0.47), in those who underwent certain vascular procedures (OR = 0.49) and those with increasing length of stay (OR = 0.90).

Conclusion

Mortality in patients with cardiogenic shock remains high despite ECMO use. Season of admission (other than Fall) and presence of specific comorbidities (Respiratory and genitourinary diseases) are associated with increased mortality in this population. Familiarity with these variables can help identify patients at higher risk of death and can help improve outcomes further in cardiogenic shock.

Electronic supplementary material

The online version of this article (10.1186/s12873-018-0171-8) contains supplementary material, which is available to authorized users.

Human cold stress of strong local-wind "Hijikawa-arashi" in Japan, based on the UTCI index and thermo-physiological responses

We investigated the cold stress caused by a strong local wind called "Hijikawa-arashi," through in situ vital measurements and the Universal Thermal Climate Index (UTCI). This wind is a very interesting winter phenomenon, localized in an area within 1 km of the seashore in Ozu City, Ehime Prefecture in Japan. When a strong Hijikawa-arashi (HA) occurred at 14-15 m s^-1, the UTCI decreased to - 30 °C along the bridge where commuting residents are the most exposed to strong and cold winds. On the bridge, most participants in our experiment felt "very cold" or "extremely cold." The UTCI of HA can be predicted from a multiple regression equation using wind speed and air temperature. The cold HA wind is also harmful to human thermo-physiological responses. It leads to higher blood pressure and increased heart rate, both of which act as cardiovascular stress triggers. Increases of 6-10 mmHg and 3-6 bpm for every 10 °C reduction in UTCI were seen on all observational days, including HA and non-HA days. In fact, the participants' body skin temperatures decreased by approximately 1.2 to 1.7 °C for every 10 °C reduction in UTCI. Thus, the UTCI variation due to the HA outbreak corresponded well with the cold sensation and thermo-physiological responses in humans. This result suggests that daily UTCI monitoring enables the prediction of thermo-physiological responses to the HA cold stress.

"Summer Shift": A Potential Effect of Sunshine on the Time Onset of ST-Elevation Acute Myocardial Infarction

Background

ST‐elevation acute myocardial infarction (STEMI) represents one of the leading causes of death. The time of STEMI onset has a circadian rhythm with a peak during diurnal hours, and the occurrence of STEMI follows a seasonal pattern with a salient peak of cases in the winter months and a marked reduction of cases in the summer months. Scholars investigated the reason behind the winter peak, suggesting that environmental and climatic factors concur in STEMI pathogenesis, but no studies have investigated whether the circadian rhythm is modified with the seasonal pattern, in particular during the summer reduction in STEMI occurrence.

Methods and Results

Here, we provide a multiethnic and multination epidemiological study (from both hemispheres at different latitudes, n=2270 cases) that investigates whether the circadian variation of STEMI onset is altered in the summer season. The main finding is that the difference between numbers of diurnal (6:00 to 18:00) and nocturnal (18:00 to 6:00) STEMI is markedly decreased in the summer season, and this is a prodrome of a complex mechanism according to which the circadian rhythm of STEMI time onset seems season dependent.

Conclusions

The “summer shift” of STEMI to the nocturnal interval is consistent across different populations, and the sunshine duration (a measure related to cloudiness and solar irradiance) underpins this season‐dependent circadian perturbation. Vitamin D, which in our results seems correlated with this summer shift, is also primarily regulated by the sunshine duration, and future studies should investigate their joint role in the mechanisms of STEMI etiogenesis.

Obesity mediated the association of exposure to polycyclic aromatic hydrocarbon with risk of cardiovascular events

Exposure to polycyclic aromatic hydrocarbons (PAHs) could cause high blood pressure (BP) and increased risk for atherosclerotic cardiovascular disease (ASCVD). However, the mechanisms underlying the relationship between them were unclear. We investigated potential mediation effect of obesity on the association of exposure to PAHs with high BP and increased risk for ASCVD. In the repeated measures study, 106 community-dwelling residents in Wuhan, China finished the physical examination in the winter and summer seasons, eight urinary PAHs metabolites were measured. Associations of urinary PAHs with high BP and increased risk for ASCVD were assessed using either linear mixed effect models or generalized estimating equations models. Mediation analysis was performed to evaluate the mediating effect of obesity on the association of urinary PAHs metabolites with high BP or increased risk of ASCVD. We observed the positive association between urinary PAHs metabolites and BP or the odds ratios for high BP (all P<0.05). Additionally, each one-unit increase in ln-transformed urinary levels of 4-hydroxyphenanthrene or the total of PAH metabolites was associated with a 12.63% or 11.91% increase in the estimated 10-year ASCVD risk (both P<0.05). The waist-to-height ratio mediated 29.0% of the association of urinary 4-hydroxyphenanthrene with increased risk of ASCVD (P<0.05). The findings suggest that PAHs exposure may be associated with elevated BP and an increased risk of ASCVD. Obesity may partially mediate the association between PAHs exposure and higher BP or increased risk of ASCVD.